Move by Riken Comes a Day After Co-Author Called for Retraction, Citing 'Crucial Mistakes'

A Japanese research institute said Tuesday it was weighing whether to retract studies that described a surprisingly easy way to make stem cells in the lab, a day after one of the co-authors said the research contained "crucial mistakes."

The co-author, Teruhiko Wakayama of Yamanashi University in Japan, called Monday for the retraction of the findings, published in late January in a pair of papers in the journal...